Standard shipping containers, i.e. those used interchangeably on ships, trains and trucks, are often broken into during transit. For example, when they are transported on a train, a thief may stow away on the train and have a long period during which to attempt a break-in. Typically, the thief will chisel open the hasp which secures the locking handle. This hasp has two main weak points. One is the relatively narrow area surrounding the hole for the locking pin of the security seal and the other is the same area around the bolts that attach the hasp to the container door.
While the hasp might be sealed with a lock, typically it will be sealed with a disposable security seal, known in the industry as a "breakaway security seal" and readily available. These seals are used because the ultimate recipient of a shipment originating abroad cannot be expected to have a key or know a combination. However, a legitimate user can readily obtain a special tool that can be used to snap open the breakaway seal, which then must be discarded. Such seals have a vertical center pin that extends through the holes in the hasp in the manner of the shackle of a padlock. With the advent of such seals, thieves now usually attack the hasp itself.
It is therefore desired to produce a hasp protector with the following characteristics. First of all, it should protect both the particular type of hasp used on shipping containers and also the special breakaway seal. Secondly, the protector should be self-supporting, so that the container need not itself be modified for its use, insofar as the container may belong to someone other than the entity applying the protector (the latter may be, for example, a railroad company). Finally, the protector should be relatively simple to construct at low cost--the railroad may never see the protector again once the container is delivered to the customer.
Prior developments in this field may be generally illustrated by reference to the following patents:
______________________________________ Patent No. Patentee Issue Date ______________________________________ 3,736,016 C. Garvey et al. May 29, 1973 4,898,008 D. Eberly Feb. 06, 1990 4,581,907 D. Eberly Apr. 15, 1986 4,389,862 T. Hastings Jun. 28, 1983 4,096,718 L. Michelman et al. Jun. 27, 1978 4,895,007 D. Eberly Jan. 23, 1990 4,324,426 T. Michelson Apr. 13, 1982 4,742,701 D. Scavetto May 10, 1988 ______________________________________
U.S. Pat. No. 4,096,718 shows a self-supporting lock protector for a lock of the general shape of the breakaway security seals used on shipping containers. The seal described therein, however, is re-usable and key-operated. The hasp is built into the protector itself. The remainder of the patents show devices for protecting key-operated locks having standard U-shaped locking shackles.
U.S. Pat. No. 3,736,016 shows a box-shaped hasp protector for truck trailers, which protector is bolted to the trailer door.
U.S. Pat. No. 4,898,008 shows a bolt-on replacement hasp which incorporates protection for the shackle of the lock.
U.S. Pat. No. 4,895,007 teaches a box-shaped security device which is self-supporting and which protects the lock and its shackle, but which does not protect the rotating portion of the hasp.
U.S. Pat. No. 4,389,862 shows a locking assembly which does not protect the hasp, but which instead secures the locking rods themselves.
The rest of the patents are representative of what is in the art.